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The Checker Framework enhances Java’s type system to make it more powerful and useful. This lets software developers detect and prevent errors in their Java programs. The Checker Framework includes compiler plug-ins ("checkers") that find bugs or verify their absence. It also permits you to write your own compiler plug-ins.

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package org.checkerframework.checker.nullness.qual;

import java.lang.annotation.*;

import org.checkerframework.dataflow.qual.SideEffectFree;
import org.checkerframework.checker.nullness.NullnessChecker;
import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.checkerframework.checker.nullness.qual.RequiresNonNull;
import org.checkerframework.framework.qual.SubtypeOf;

/**
 * This annotation is deprecated.  {@link MonotonicNonNull} should be used
 * instead.
 * 
 *
 * Indicates that a field (or variable) is lazily initialized to a non-null
 * value.  Once the field becomes non-null, it never becomes null again.
 * There is no guarantee that the field ever becomes non-null, however.
 * 

 *
 * Lazily initialized fields have these two properties:
 * 

 * The field may be assigned only non-null values.
 * The field may be re-assigned as often as desired.
 * 
 * 
 *
 * When the field is first read within a method, the field cannot be
 * assumed to be non-null.  After a check that a {@code LazyNonNull} field
 * holds a non-null value, all subsequent accesses within that
 * method can be assumed to be non-null, even after arbitrary external
 * method calls that might access the field.
 * 

 *
 * {@code LazyNonNull} gives stronger guarantees than {@link Nullable}.
 * After a check that a {@link Nullable} field holds a non-null value, only
 * accesses until the next non-{@link SideEffectFree} method is called can be assumed
 * to be non-null.
 * 

 *
 * To indicate that a {@code LazyNonNull} or {@code Nullable} field is
 * non-null whenever a particular method is called, use
 * {@link RequiresNonNull}.
 * 

 *
 * Final fields are treated as LazyNonNull by default.
 * 
 *
 * This annotation is associated with the {@link NullnessChecker}.
 *
 * @see Nullable
 * @see NullnessChecker
 * @checker_framework.manual #nullness-checker Nullness Checker
 */
@Deprecated
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE_USE) // not applicable to ElementType.TYPE_PARAMETER
@SubtypeOf(Nullable.class)
public @interface LazyNonNull {}